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Expired Canadian patentCanada

Low striation positive resist composition

CA 1213769 A · Owner: Petrarch Systems Inc. · Inventors: Owens, Robert A.; Lewis, James M.; Rinehart, Robert E.

CIPO record

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Abstract From the Canadian patent

A novel photoresist formulation is provided which provides low striations and excellent wetting properties. The photoresist composition may be applied by spin casting on various substrates used in integrated circuit manufacture. The essential component in this invention is the solvent composition which consists of cyclopentanone (or cyclopentanone-cyclohexanone blend) in combination with an aliphatic alcohol of 5-12 carbon atoms. These solvent components when used in certain specific ratios provide unexpectedly good wetting of various substrates and low striation films.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted November 12, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 12, 2003.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 19, 1984
GrantedNovember 12, 1986
Term endedNovember 12, 2003
Patent numberCA 1213769 A
Classification (IPC)G03C1/54 +2 more

Timeline

Timeline From CIPO dates

1985198719891991199319951997199920012003Application filedApril 19, 1984Patent grantedNov 12, 1986Term endedNov 12, 2003

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.